US 4,686,058 A · Thickened-water based hydraulic fluids

Abstract

This invention relates to thickened high-viscosity water based hydraulic fluids. Such fluids are prepared by blending water, organic thickener and conventional hydraulic fluid additives. Organic thickeners tend to lose their thickening effect with time, and particularly when subjected to oxidizing agents, heat, prolonged use in a pump, etc. In accordance with the instant invention, preservation of the thickener, particularly with respect to viscosity loss, is achieved by blending with the final fluid a fluid concentrate, or the thickener itself, a compound selected from the group consisting of ethylene glycol, propylene glycol, propylene glycol polymers and copolymers containing at least 50 percent by weight of oxypropylene groups, a dimercaptothiadiazole, neodecanoic acid, a hindered phenol antioxidant and mixtures thereof.

Claims10

Dependent claims

A hydraulic fluid composition comprising water;

an organic thickener which is a polyether polyol having a molecular weight of about 100 to about 40,000 prepared by reacting ethylene oxide or ethylene oxide and at least one lower alkylene oxide having 3 to 4 carbon atoms with at least one active hydrogen-containing compound and at least one alpha-olefin oxide or glycidyl ether having a carbon chain of about 10 to about 22 aliphatic carbon atoms wherein said alpha-olefin oxide or glycidyl ether is present in the amount of 1 to about 20 percent by weight based upon the total weight of said thickener;
and a polyoxyalkylene polymer or copolymer having at least 50 percent by weight oxypropylene groups and an average molecular weight of about 75 to about 5000.

A process for preparing a hydraulic fluid comprising blending water;

an organic thickener which is a polyether polyol having a molecular weight of about 100 to about 40,000 prepared by reacting ethylene oxide or ethylene oxide and at least one lower alkylene oxide having 3 to 4 carbon atoms with at least one active hydrogen-containing compound and at least one alpha-olefin oxide or glycidyl ether having a carbon chain length of about 10 to about 22 aliphatic carbon atoms wherein said alpha-olefin oxide or glycidyl ether is present in the amount of 1 to about 20 percent by weight based upon the total weight of said thickener;
and a polyoxyalkylene polymer or copolymer containing at least 50 percent by weight of oxypropylene groups and an average molecular weight of about 75 to about 5000.

Dependencies are inferred from the claim text.

Thickened-water based hydraulic fluids

Life of this patent

Thickened-water based hydraulic fluids

Life of this patent

Abstract

Claims10